U.S. patent number 6,331,352 [Application Number 09/373,908] was granted by the patent office on 2001-12-18 for correction tape having dye migration blocking properties.
This patent grant is currently assigned to Bic Corporation. Invention is credited to Creg G. Bradley, Peter D. Gabriele, Teresa B. Hopper.
United States Patent |
6,331,352 |
Bradley , et al. |
December 18, 2001 |
Correction tape having dye migration blocking properties
Abstract
The present invention is directed to correction tapes having dye
migration blocking properties. More specifically, the present
invention includes a correction tape having a dye migration
barrier. The dye migration barrier comprises an organic material
that serves as a physical barrier to prevent dye from migrating
from the lower corrected layer to the visible surface.
Additionally, the present invention is directed to a process for
the manufacture of a correction tape having a dye migration
barrier.
Inventors: |
Bradley; Creg G. (Simpsonville,
SC), Hopper; Teresa B. (Belton, SC), Gabriele; Peter
D. (Simpsonville, SC) |
Assignee: |
Bic Corporation (Milford,
CT)
|
Family
ID: |
23474389 |
Appl.
No.: |
09/373,908 |
Filed: |
August 13, 1999 |
Current U.S.
Class: |
428/354; 428/343;
428/355AC; 428/906 |
Current CPC
Class: |
C09J
7/29 (20180101); C09D 10/00 (20130101); Y10T
428/28 (20150115); Y10T 428/2891 (20150115); C09J
2301/162 (20200801); C09J 2400/163 (20130101); C09J
2433/00 (20130101); C09J 2431/001 (20130101); Y10S
428/906 (20130101); Y10T 428/2848 (20150115); C09J
2400/283 (20130101); C09J 2423/001 (20130101) |
Current International
Class: |
C09D
10/00 (20060101); C09J 7/02 (20060101); C09J
007/02 (); B32B 007/12 () |
Field of
Search: |
;428/354,343,355AC,906 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
|
|
647689 |
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Dec 1995 |
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EP |
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647689 A1 |
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Dec 1995 |
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EP |
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727378 A1 |
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Aug 1996 |
|
EP |
|
8258494 |
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Oct 1996 |
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JP |
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WO 92/07039 |
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Apr 1992 |
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WO |
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WO 94/29393 |
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Dec 1994 |
|
WO |
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WO 96/01878 |
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Jan 1996 |
|
WO |
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WO 98/30641 |
|
Jul 1998 |
|
WO |
|
Primary Examiner: Zirker; Daniel
Attorney, Agent or Firm: Pennie & Edmonds LLP
Claims
What is claimed:
1. A correction tape comprising:
a first layer which is a support member with sufficient rigidity to
hold at least a second, third, and fourth layer;
the second layer comprising a correction medium layer;
the third layer comprising a dye migration barrier; and
the fourth layer comprising a pressure sensitive adhesive layer
present in sufficient amount to form a layer of a thickness to
adhere the second and third layer to a substrate,
wherein the second and third layers are interposed between the
first and fourth layers.
2. The correction tape according to claim 1, wherein the support
member is paper, thermoplastic film, or metallic foil.
3. The correction tape according to claim 1, wherein the support
member is a coated glassine paper.
4. The correction tape according to claim 1, further comprising a
support member which is coated with a releasing agent.
5. The correction tape according to claim 4, wherein the releasing
agent is a polyolefin, polysiloxane, polyfluoroolefin, or a mixture
thereof.
6. The correction tape according to claim 1, wherein the dye
migration barrier comprises at least one organic polymer.
7. The correction tape according to claim 6, wherein the organic
polymer comprises at least one acrylate, methacrylate, styrene,
styrene acrylic, styrene butadiene, vinyl acetate homopolymer,
vinyl acetate, vinyl acetate ethylene, or cellulose.
8. The correction tape according to claim 6, wherein the organic
polymer comprises at least one ethylene, vinyl acetate, or ethylene
vinyl acetate.
9. The correction tape according to claim 1, wherein the dye
migration barrier is between about 1 micron to about 100 microns in
thickness.
10. The correction tape according to claim 1, wherein the dye
migration barrier is between about 3 microns to about 5 microns in
thickness.
11. The correction tape according to claim 1, wherein the pressure
sensitive adhesive comprises at least one organic polymer made from
monomers of acrylic, or methacrylic.
12. The correction tape according to claim 1, wherein the dye
migration barrier retains correction medium integrity.
13. The correction tape according to claim 4, wherein the releasing
agent is present in an amount sufficient to form a layer of a
thickness of about 0.1 microns to about 25 microns.
14. The correction tape according to claim 4, wherein the releasing
agent is present in an amount sufficient to form a layer of a
thickness of about 5 microns to about 10 microns.
15. The correction tape according to claim 1, wherein the dye
migration barrier is layered to a thickness of about 3 microns to
about 45 microns.
16. A correction tape comprising:
a first layer which is a support member with sufficient rigidity to
hold at least a second, third, and forth layer;
the second layer disposed upon the first layer is an organic
polymer layered to a thickness sufficient to mask printed or ink
matter on a substrate to form a correction medium layer;
the third layer disposed upon the second layer is a dye migration
barrier layered to a thickness sufficient to prevent ink from
traversing from the substrate and through the second layer; and
the fourth layer disposed upon the third layer and which is a
pressure sensitive adhesive present in sufficient amount to form a
layer of a thickness sufficient to adhere the second and third
layer to a substrate.
Description
BACKGROUND OF THE INVENTION
The present invention is directed to correction tapes having dye
migration blocking properties. More specifically, the present
invention includes a correction tape having a dye migration
barrier. The dye migration barrier comprises an organic material
that serves as a physical barrier to prevent ink dye from markings
covered by the correction tape from migrating to an upper visible
surface of the correction tape. Additionally, the present invention
is directed to a process for the manufacture of a correction tape
having a dye migration barrier.
Correction tape is a commonly used method to cover markings. The
tape typically comprises two parts, a polymeric support member as a
base and a correction medium releasably attached to the base. A
correction medium may be multi-layered, and may contain pigments,
fillers, such as clay, a polymeric binder and dispersant to anchor
the pigments to the paper, as well as, a dispersant medium or
solvent to maintain fluid viscosity. The correction medium is later
transferred onto paper to cover markings once pressure is applied
on the tape.
Conventional correction tapes typically allow ink dyes from the
covered markings to bleed through the applied correction medium.
The dissolution of the underlying ink dyes from the reaction of the
ink dye with the correction medium causes the so-called bleeding or
smudging of the markings into the correction medium, which
discolors the correction medium on the corrected marking. Bleeding
causes the typically white correction medium to assume a bluish or
reddish tint or other type of blemish color due to the ink dye
migrating toward the upper visible surface of the layer of
correction medium. This bleeding effect is a known shortcoming of
conventional correction tapes.
Correction fluids have been developed to solve the problem of
bleed-through. See, European Publication No. 0 647 689 A1, PCT
Publication No. WO 92/07039, PCT Publication No. WO 94/29393, PCT
Publication No. WO 96/01878, and PCT Publication No. WO
98/30641.
Japanese Patent No. 2,692,642 discloses a correction tape
comprising a correction material, a metal thin film layer, and an
adhesive layer. The metal thin film layer provides a masking
effect. The correction medium layer has the same color tone as that
of a plain paper effected by incorporating a white pigment into a
resin material or by providing a white printing layer on the
surface of the base material layer. The correction tape
manufactured with a metal thin film layer is costly because the
metal thin film layer is applied using specialized vapor deposition
techniques instead of standard layering techniques. Additionally,
the vapor deposition of a metal requires harsh manufacturing
conditions that strain the correction medium layer such as high
temperatures, low pressures, and drying periods under vacuum.
Some of the commercially available correction tape products are
made using polymers dissolved in organic solvents which provide
some protection against bleeding, however, environmental
regulations restrict the use of organic solvents on an industrial
scale due to pollution problems. Measures taken to decrease the
environmental impact of the use of organic solvents increase
production costs of correction tapes. Other commercial products do
not have adequate bleed inhibiting characteristics.
Despite these efforts correction tapes having better bleed through
resistance are still desired by the industry. As new water and
solvent based ink compositions are developed, new compositions and
formulations of correction tapes are necessary to maintain good
bleed through resistance.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a correction tape
that inhibits bleed-through through the correction medium when
applied to printed or ink dye markings.
Another object of the present invention is to provide a
manufacturing process for a correction tape with a dye migration
barrier.
Another object of the present invention is that film integrity of
the correction tape is improved thus avoiding premature breakage,
as found in current correction tapes.
Yet another object of the present invention is to provide a
manufacturing process that does employ environmentally friendly
chemicals and chemical processes.
The present invention is directed to a correction tape comprising
at least one support member, at least one correction medium, at
least one dye migration barrier, and at least one pressure
sensitive adhesive layer. The support member retains a correction
medium, dye migration barrier and an adhesive layer. Typically the
support member is paper, thermoplastic film, a metallic foil, or a
coated glassine paper to facilitate removal of the correction
medium. Optionally, the support member can be coated with a
releasing agent, such as a polyolefin, polysiloxane,
polyfluoroolefin, or a mixture thereof. The dye migration barrier
is present in an amount sufficient to prevent ink from migrating
through at least the dye migration barrier and retain correction
medium integrity when the correction medium is transferred to a
surface. The dye migration barrier is typically an organic polymer
or copolymer made of acrylate, methacrylate, styrene, styrene
acrylic, styrene butadiene, vinyl acetate homopolymer, a low
volatile organic compound, vinyl acetate, vinyl acetate ethylene,
cellulose, or copolymers thereof. Preferably, the organic polymer
comprises at least one ethylene, vinyl acetate, ethylene vinyl
acetate, or copolymers thereof. The dye migration layer thickness
may be between about 1 micron to about 100 microns in thickness,
preferably, between about 3 microns to about 45 microns.
The pressure sensitive adhesive typically includes at east one
organic polymer made from monomers of acrylic, ethacrylic, or a
mixture thereof.
Another aspect of the present invention includes a process for the
manufacture of a correction tape having the steps of providing a
support member; applying a correction material in a sufficient
amount onto the support member to form a first layer, a correction
medium, preferably with a thickness of between about 40 to about 60
microns when wet; allowing the first layer to dry to form a
correction medium; applying an organic polymer to the first layer
in a sufficient amount to form a second layer, preferably with a
thickness of between about 3 micron to about 5 microns; allowing
the second layer to dry to form a dye migration barrier; applying
an adhesive material to the second layer in a sufficient amount to
form a third layer; and allowing the third layer to dry.
Optionally, the process includes a curing step wherein either the
first, second, or third layer is allowed to cure after drying, at
about room temperature and for a minimum time of about 24 hours.
Optionally, the process includes coating the support member with a
releasing agent such as polyolefin, polysiloxane, polyfluoroolefin,
or a mixture thereof in a sufficient amount to facilitate the
release of the correction medium and dye migration barrier from the
support member. The process may include a step wherein the
correction tape is slitted to a width of about 4.2 mm.
The drying step within the process can be performed in a drying
tunnel having at least one IR lamp, convection oven, hot air
blower, or a combination thereof.
The organic polymer of the process can be at least one acrylate,
methacrylate, styrene, styrene acrylic, styrene butadiene, vinyl
acetate homopolymer, a low volatile organic compound, vinyl
acetate, vinyl acetate ethylene copolymer, cellulose, or copolymers
thereof, preferably at least one of ethylene, vinyl acetate,
ethylene vinyl acetate, or copolymers thereof. The releasing agent
can be a polyolefin, polysiloxane, polyfluoroolefin, or a mixture
thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates one embodiment of the invention wherein a
correction tape (2) has a support layer (1), a correction medium
layer (3), a dye migration layer (5), and a pressure sensitive
adhesive layer (7).
FIG. 2 illustrates one embodiment of the invention wherein a
correction tape (4) has a support layer (1), a release layer (9), a
dye migration layer (5), a correction medium layer (3), and
pressure sensitive adhesive layer (7).
DETAILED DESCRIPTION OF THE INVENTION
The present invention resolves the problem of bleed-through of dyes
through correction tape by incorporating a dye migration barrier,
that works as a physical barrier within the correction tape. The
dye migration barrier maintains correction medium cohesiveness by
reducing tape brittleness by providing an organic polymeric layer
that aids to support the correction medium. Additionally, the
present invention provides a process for the manufacture of a
correction tape with a dye migration barrier.
One embodiment of the invention provides a multiple layered
correction tape that increases bleed-through resistance. The
invention comprises a support member or backing, a pressure
sensitive adhesive (PSA) layer, an correction medium, and a dye
migration barrier. The latter has a dual effect; it decreases ink
bleed-through and improves film integrity. The dye migration
barriers preferably has good bleed resistance when used to cover
ink marks. As used herein, the term "ink" or "inks" means an ink
which is either water based or solvent based and which is deposited
from writing instruments or printing devices or other means. The
invention further comprises a support member or backing, optionally
coated with a releasing agent and a pressure sensitive adhesive
layer.
Suitable support members can be coiled into rolls and used in
correction tape dispensers. Suitable correction tape dispensers
include those disclosed in European Publication No. EP 727378 A1.
Preferred materials for the support member include paper, plastic
films, such as polyester, polycarbonate, polyacrylic, polyolefin,
polystyrene, etc., and metal foils such as aluminum, zinc, brass,
etc. More preferred support members include controlled release
siloxane double coated glassine paper such as Item #17513 (50 lb.
white coated two sided moderate release) manufactured by
Siltech.
Preferably, the support member is coated with a releasing agent.
The releasing agent can be a polyolefin, polysiloxane,
polyfluoroolefin, a silicone based material, or mixtures thereof.
More preferably, the releasing agent is a high molecular weight
polyolefin, i.e., a polyolefin with a M.sub.n of at least 20,000, a
polysiloxane, a polytetrafluoroolefin, or a mixture thereof. The
releasing agent should be present in sufficient amounts to lightly
coat the support member and aid the release of the correction
medium and dye migration barrier from the support member onto the
surface to be corrected. The releasing agent can form a layer of a
thickness between about 0.1 microns to about 25 microns.
Preferably, the releasing agent layer should be between about 0.5
microns to about 15 microns, more preferably between about 5
microns to about 10 microns.
The term "dye migration barrier" means a physical layer which, when
present, prevents or decreases the amount of ink migrating from one
surface of the layer of the correction medium onto the opposite
surface of the layer. The dye migration barrier is preferably an
organic polymer.
As used in the present invention, "organic polymer" means a
chemical polymer comprising monomers containing mostly carbon and
hydrogen, and if desired oxygen, nitrogen, sulfur, halides, or
mixtures thereof. The organic polymer may comprise one or more type
of monomers, which can be either saturated or unsaturated. Such
organic polymers typically include acrylate, methacrylate, styrene,
styrene acrylic, styrene butadiene, vinyl acetate homopolymer, low
volatile organic compound (VOC) vinyl acetate, vinyl acetate
ethylene copolymers, cellulose and mixtures thereof.
Preferably the organic polymers include
acrylonitrile/butadiene/styrene resin, alginic acid sodium salt,
butyl methacrylate/isobutyl methacrylate copolymer, cellulose
acetate, cellulose acetate butyrate, cellulose propionate,
cellulose triacetate, ethyl cellulose, ethylene/acrylic acid
copolymer, ethylene/ethyl acrylate copolymer, ethylene/propylene
copolymer, ethylene/vinyl acetate copolymer, hydroxybutyl methyl
cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose,
methyl cellulose, methyl vinyl ether/maleic acid copolymer, methyl
vinyl ether/maleic anhydride, nylon, phenoxy resin, polyacetal,
polyacrylamide, poly(acrylic acid), polyamide resin,
1,2-polybutadiene, poly(1-butene), poly(n-butyl methacrylate),
polycaprolactone, polycarbonate resin, poly(diallyl isophthalate),
poly(diallyl phthalate), poly(2,6-dimethyl-p-phenylene oxide),
poly(4,4-dipropoxy-2,2-diphenyl propane fumarate), poly(ethyl
methacrylate), polyethylene, polyethylene chlorinated, polyethylene
chlorosulfonated, poly(ethylene oxide), poly(ethylene
terephthalate), poly(2-hydroxyethyl methacrylate), poly(isobutyl
methacrylate), polyisoprene, poly(methyl methacrylate),
poly(4-methyl-1-pentene), poly(methylstyrene), poly((p-phenylene
ethersulphone), poly(phenylene sulfide), polypropylene,
polystyrene, polysulfone resin, poly(tetrafluoroethylene),
poly(2,4,6-tribromostyrene), poly(vinyl acetate), poly(vinyl
alcohol), poly(vinyl butyral), poly(vinyl chloride), poly(vinyl
formal), poly(vinyl pyrrolidone), poly(vinyl stearate),
poly(vinylidene fluoride), styrene/acrylonitrile copolymer,
styrene/allyl alcohol copolymer, styrene/butadiene copolymer,
styrene/butyl methacrylate copolymer, styrene/ethylene/butylene
copolymer, styrene/isoprene copolymer, styrene/maleic anhydride
copolymer, vinyl alcohol/vinyl butyral copolymer, vinyl
chloride/vinyl acetate copolymer, vinyl chloride/vinyl
acetate/hydroxypropyl acrylate, vinyl chloride/vinyl acetate/vinyl
alcohol, vinylidene chloride/acrylonitrile copolymer, vinylidene
chloride/vinyl chloride copolymer, N-vinyl pyrrolidone/vinyl
acetate copolymer, zein, poly(ethyl acrylate), poly(isopropyl
acrylate), poly(n-butyl acrylate), poly(isobutyl acrylate),
poly(hexyl acrylate), poly(decyl acrylate), poly(lauryl acrylate),
poly(hexyl methacrylate), poly(cyclohexyl methacrylate),
poly(lauryl methacrylate), poly(p-t-butylstyrene), polystyrene
sulfonate, poly(vinylbenzyl chloride), poly(vinyl toluene), and
mixtures thereof. More preferably, the organic polymer includes
polymers and copolymers of ethylene, vinyl acetate, ethylene vinyl
acetate. Organic polymers are available commercially such as ELVACE
733, ELVACE 735, ELVACE 40722, and ELVACE 97955 manufactured by
Reichhold Chemical Co., 2400 Ellis Road, Durham, N.C.
27703-5543.
The dye migration barrier should be present in an amount sufficient
to create a physical barrier. The dye migration barrier is
preferably positioned between the pressure sensitive adhesive layer
and correction medium. The dye migration barrier should be between
about 1 micron to about 100 microns thick, preferably between about
3 microns to about 45 microns, and more preferably between about 8
microns to about 10 microns thick.
The correction medium includes compounds having adequate masking
property to cover ink marks. The correction medium may optionally
include compounds that carry opacifying pigment onto the support
member or backing, as well as onto the paper or other substrate
that contains the markings to be masked. Any material commonly
known in the art is suitable as a correction medium or opacifying
pigment. The correction medium may be white, off-white, or any
other color suitable to match the surface upon which the correction
tape is applied.
The pressure sensitive adhesive includes compounds capable of
adhering the correction medium to the paper or other substrate.
Suitable pressure sensitive adhesives include National Starch &
Chemical (NACOR 4554, 8685, 9926), H. B. Fuller (FULATEX PN-3181-K,
PN-3819-G), BASF (ACRONAL V275, A220, 3432), Franklin International
(COVINAX 210-00, 225-00, 222-00).
Another aspect of the invention includes a process for the
manufacture of a correction tape having a dye migration barrier.
The process of forming a correction tape comprises the step coating
the support member with an correction medium followed by a first
curing period. Thereafter, coating the tape with the correction
medium with an organic polymer to form a dye migration barrier,
followed by a second curing period. Subsequently, applying a
coating of pressure sensitive adhesive to the tape with the dye
migrating barrier to form a correction tape. Optionally, the
process may contain a step wherein the support member is coated
with a releasing agent prior to applying to the opacifying
layer.
The step of applying a correction material to the support member to
form a correction medium comprises coating the support member with
the correction material using methods commonly known in the art,
such as by gravure coating or by the Mayer rod technique. Typically
the coating process comprises the steps of rolling the support
member into the unwind end of a coating machine, moving the support
member at a desired rate, and depositing the white opaque
correction material into the coating head area at a rate of between
about 1 gallon per hour to about 40 gallons per hour, preferably at
a rate of between about 15 gallons per hour to about 25 gallons per
hour. Once the desired amount and continuity of coating film is
achieved, the coating process further comprises the steps of
increasing the rate of speed of the support member to a nominal
coating speed; and subsequently, drying and curing the tape. The
white opacifying material can be applied at a viscosity of between
about 15 cps to about 200 cps, preferably between about 25 cps to
about 40 cps and at a pH of between about 7.5 to about 9.5,
preferably at a pH of between about 8 to about 9. The wet coating
thickness is typically between about 40 and about 60 microns, which
is reduced to a typical thickness of between about 20 microns to
about 30 microns after the curing process, preferably the thickness
is between about 24 microns to about 28 microns, more preferably
between about 26 to about 28 microns.
The drying step can be carried out by conventional means in the
art, such as a drying tunnel. The drying tunnel may be heated using
lamps, convection heat, hot air, or a combination thereof,
preferably hot air. Typically a drying tunnel is heated by one or
more IR lamps, convection heating elements, blowing hot air, or a
combination thereof. The temperature of the drying tunnel ranges
between about 40.degree. C. to about 110.degree. C. Preferably, the
drying tunnel temperature ranges between about 40.degree. C. to
about 50.degree. C. when using IR lamps, and between about
40.degree. C. to about 110.degree. C. when using convection heating
elements. During the curing step the roll is hung horizontally for
at least 24 hours.
Prior to coating the support member with a correction medium, the
support member may optionally be coated with a releasing agent.
Preferably, the coating should be at least one silicone releasing
agent in sufficient amount to aid the release of the correction
tape from the support member during normal use of the correction
tape.
The application of the dye migration barrier material to coat the
correction medium comprises applying an organic polymer in a
sufficient amount to prevent the migration of dye or ink across the
dye migrating barrier. The step of applying an organic polymer to
the correction medium to form a dye migration barrier typically
comprises applying a coating of organic polymer to the correction
medium using techniques commonly known in the art, such as gravure
roll or the Mayer rod technique, followed by a curing period. The
steps comprise placing the tape with the correction medium from the
previous step into the unwind end of a coating machine. Layering
the organic polymer using roll speeds and drying settings of the
previous step, followed by a second curing period. The rate of
deposition of the organic polymer should be between about 1
meter/min to about 1000 meters/min, preferably between about 10
meters/min to about 200 meters/min, and more preferably between
about 20 meters/min to about 50 meters/min. The organic polymer
should have a viscosity between about 10 cps to about 5000 cps,
preferably between about 50 cps and about 500 cps, more preferably
between about 50 cps and about 100 cps. The dye migrating barrier
typically has a wet thickness of between about 9 microns to about
25 microns, preferably between about 10 microns to about 15
microns. After the curing process, a typical dry dye migration
barrier thickness is between about 2 microns to about 10 microns,
preferably between about 3 microns to about 5 microns. During the
curing step the roll is hung horizontally for at least 24
hours.
Applying the pressure sensitive adhesive to the dye migrating
barrier layer can be carried out using methods commonly known in
the art, such as by gravure coating or by the Mayer rod technique.
A typical step comprises depositing a pressure sensitive adhesive
onto the dye migrating barrier using the techniques described
above, followed by drying and a curing period of at least about 24
hours. The pressure sensitive adhesive is typically coated at a
viscosity of between about 10 cps to about 60 cps, preferably at a
viscosity of about 30 cps, and at a pH of between about 3 to about
5, preferably at a pH of about 4.5. Thereafter, the roll may
optionally be slitted to a desired width using techniques commonly
known in the art. Preferably, the tape width is between about 3 mm
to about 10 mm, more preferably the tape width is about 4.2 mm.
The following description of the figures is meant only as an
illustration of embodiments of the invention and is not meant to be
a limitation. FIG. 1 illustrates one embodiment of the invention
wherein the correction tape (2) has at least one support layer (1),
correction medium layer (3), dye migration layer (5), and pressure
sensitive adhesive layer (7). FIG. 2 illustrates another embodiment
of the invention wherein a correction tape (4) has at least one
support layer (1), the optional release layer (9), dye migration
layer (5), correction medium layer (3), and pressure sensitive
adhesive layer (7).
EXAMPLES
Certain embodiments and features of the invention are now
illustrated, but not limited, by the following working
examples.
Example 1
A correction tape having a dye migration barrier was manufactured
by placing a roll of paper support member into the unwind end of a
coating machine. Using a gravure coating technique, the paper was
moved at a rate of about 10 m/min; concurrently, a white opaque
correction medium was pumped in the coating machine at a rate of
between about 15 gallons/min to about 25 gallons/min. Afterwards,
the speed was increased to 20 m/min while the engraved gravure roll
rotated in the opposite direction of the base of the paper at a
speed of about 4.8 m/min. When the engraved gravure roll was
covered with white opaque correction medium, a nip roll was lowered
down until the distance between the gravure roll and the nip was
about 0.2 mm. The liquid white opaque correction medium was applied
at a viscosity of between about 25 cps to about 40 cps and at a pH
of between about 8 to about 9. Thereafter, the roll was passed
through a drying tunnel consisting of three conventionally heated
ovens at temperatures of 45.degree. C., 65.degree. C., and
100.degree. C., respectively. The rolled was hung horizontally for
a minimum of 24 hours prior to applying the dye migration
barrier.
The roll from the previous step was inserted into the unwind end of
the coating machine, and the tape was coated with an organic
polymer using the settings set forth in the previous step. The wet
coating thickness was between about 10 microns to about 15 microns,
resulting in a dry dye migration barrier layer of between about 3
microns to about 5 microns. Afterwards, the roll was hung
horizontally for a minimum of 24 hours at 25.degree. C.
The roll from the previous step was inserted into the unwind end of
coating machine, and the tape was coated with a PSA, applied at the
same speed and oven settings as previously described. The PSA was
coated at a viscosity of about 20 cps with a pH of about 4.5.
Afterwards, the roll was hung horizontally for a minimum of 24
hours prior to slitting to width.
Using the procedure described above, four correction tapes in
accordance to the present invention were fabricated. Tape #1
contained ELVACE 733 as the organic polymer, Tape #2 contained
ELVACE 735 as the organic polymer, Tape #3 contained ELVACE 739,
and Tape #4 contained ELVACE 97955 as the organic polymer.
These samples were evaluated to determine bleed-through resistance.
Bleed-through resistance was determined using the following
methodology. A test sheet, preferably long grain white 8.5
in.times.11 in, 75 g/m, was marked with horizontal lines
approximately 1 inch long with each of four to seven test inks (BIC
Round Stick Black, BIC Round Stick Blue, BIC Round Stick Red (old
and new), Cross Red Medium 8515, Rose Art Black, Rose Art Blue,
Rose Art Red). One set of lines was made with the four to seven ink
pens for each sample to be evaluated. Each of the correction tape
samples tested was applied over the ink pen markings on the test
sheet by the "nose" or tip of a correction tape applicator. The
test sheet was kept in an environment of about 23.degree. C. and
about 30% relative humidity for 24 hours. A correction tape sample
with minimal ink bleed-through after 24 hours was judged to have
improved ink bleed-through qualities.
The correction tapes of the present invention were applied onto
various markings on white bond paper and their masking ability was
compared. The results were obtained by matching the resulting
bleed-through color with the Pantone.RTM. Color Formula Guide and
reporting the color number which most resembled the bleed-through
color. Results are as follows:
TABLE I Test Ink BIC BIC Rose Rose Rose Tape BIC Old New Cross Art
Art Art Sample Black Red Red Red (Black) (Blue) (Red) TIPP EX 428c
494c 495c 495c 428c 278c 495c TE/Lab* 428c 495c 496c 496c <427c
<227c 496c Tombow N/O <503C N/O 503c N/O N/O 503c Tape #1 N/O
495c <503c 502c N/O N/O 502c Tape #2 N/O 502c <503c 502c N/O
N/O 502c Tape #3 N/O N/O N/O N/O N/O N/O <503c Tape #4 N/O N/O
N/O N/O N/O N/O N/O *TE/Lab is a correction tape made in a
laboratory following the description for the manufacture of the
commercially available TIPP EX correction tape. N/O = color not
observable; <= lighter than.
Example 2
Using the procedure described in Example 1, seven additional
correction tapes were made. Tape #5 contained WORLECRYL 7712E as
the organic polymer, Tape #6 contained WORLECRYL 7712E as the
organic polymer in a 1:1 mixture with water, Tape #7 contained
WORLECRYL 7712W (25% solids) as the organic polymer, Tape #8
contained WORLECRYL 7712W as the organic polymer in a 1:1 mixture
with water, Tape #9 contained WORLECRYL 7712 IPA as the organic
polymer, Tape #10 contained WORLECRYL 7712 IPA as the organic
polymer in a 1:1 mixture with water, and Tape #11 contained AQUAREZ
7G as the organic polymer.
These samples of correction tapes, as described above, were applied
onto various markings on white bond paper and their masking ability
was compared. Results are as follows:
TABLE II Test Ink Tape Sample BIC Black BIC Old Red BIC New Red
Rose Art (Red) TIFF EX 428c 494c 495c 495c TE/Lab* 428c 495c 496c
496c Tombow N/O <503c N/O 503c Tape #5 N/O N/O N/O <503c Tape
#6 N/O <503c N/O <503c Tape #7 N/O <503c N/O N/O Tape #8
N/O 502c 502c 502c Tape #9 N/O <503c N/O <503c Tape #10 N/O
503c <503c <503c Tape #11 N/O 503c <503c <503c *TE/Lab
is a correction tape made in a laboratory following the description
for the manufacture of the commercially available TIPP EX
correction tape.
Example 3
Using the procedure described in Example 1, four additional
correction tapes were made. Tape #12 contained ABCO E700 as the
organic polymer, Tape #13 contained ABCO NH-44 as the organic
polymer, Tape #14 contained a 1:1 POLYSAT HCRE-ELVACE 735 mixture
as the organic polymer, and Tape #15 contained a 1:1 POLYSAT
HCRE-ELVACE 739 mixture as the organic polymer.
The correction tapes of the present invention, as described above,
were applied onto various markings on white bond paper and their
masking ability was compared. Results are as follows:
TABLE III Test Ink Tape Sample BIC Black BIC Old Red BIC New Red
Rose Art Red TIPP EX 428c 494c 495c 495c TE/Lab* 428c 495c 496c
496c Tombow N/O <503c N/O 503c Tape #12 N/O 501c 502c 501c Tape
#13 427c 501c 501c 501c Tape #14 N/O 501c 501c 502c Tape #15
<427c 501c 502c 502c *TE/Lab is a correction tape made in a
laboratory following the description for the manufacture of the
commercially available TIPP EX correction tape.
The invention described and claimed herein is not to be limited in
scope by the specific embodiments herein disclosed, since these
embodiments are intended as illustrations of several aspects of the
invention. Any equivalent embodiments are intended to be within the
scope of this invention. Indeed, various modifications of the
invention in addition to those shown and described herein will
become apparent to those skilled in the art from the foregoing
description. Such modifications are also intended to fall within
the scope of the appended claims.
* * * * *